No, I actually do not know how those terms came about. (But I do know other, even more obscure things. Like what material was used for zeppelins gas bags. And that there were two general types of rigid airship during the first world war: metal framed and wood framed. The wood framed ones had serious problems with the laminate in the wood failing due to the temperature differences between ground level and the temperature at their cruising altitude. Alas,k I am not certain what exactly their cruising height was, although 20,000 feet sounds about right.)

TPBM wonders why on Earth I've studied airships so much when it has nothing whatsoever to do with any of the jobs I have ever held.

"Nothing is withheld from us which we have conceived to do.Do things that have never been done."--Russell Kirsch